1. Field of the Invention
The present invention relates to a solar collector, and more particularly to a solar energy collecting system.
2. Description of the Prior Art
Typical energies in earth have become less such that solar collectors have been developed for collecting the solar energy in order to substitute the other energies. One type of the solar collectors provides a sensor engaged in the tube of the solar collector so as to sense the temperature of the fluid. When the sensor is lower then a predetermined value, for example, 50.degree. C., the solar collector is stopped and may not collect the solar energy. However, a great amount of the solar energy can not be suitably collected.
The other type of the solar collector includes a sensor engaged in the tube of the solar collector and includes another sensor engaged in the water tank which is provided for collecting the heated water. The solar collector may be energized and may be operated only when the temperature difference between the two sensors reaches a predetermined temperature difference, 20.degree. C. for example. If the temperature difference does not reach the predetermined value, the solar collector can not be energized. However, similarly, a great amount of the solar energy can not be suitably collected.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional solar collectors.